RFR: 8004518 & 8010122 : Default methods on Map
akhil.arora at oracle.com
Fri Apr 12 12:50:38 PDT 2013
a few small things -
is missing Objects.requireNonNull(action);
should just return instead of throwing UnsupportedOpEx
particularly since EmptyList.replaceAll also returns silently
after checking if function is null to fulfil the NPE contract
is missing a synchronized override of forEach
is missing from the patch (won't compile without it)
On 04/11/2013 01:03 PM, Mike Duigou wrote:
> Another revision incorporating primarily documentation feedback.
> I've also included the java.util.Collections overrides for the default methods. All of these are performance enhancements--the semantics were already correct because the defaults use only public methods.
> This is likely, modulo formatting of the source examples, the version that will be pushed to TL on Friday unless somebody squawks.
> Moving the current compute, computeIfPresent, computeIfAbsent and merge defaults to ConcurrentMap and replacing the current Map defaults with versions that throw ConcurrentModificationException will likely be resolved in a future issue if the EG determines it to be important.
> On Apr 10 2013, at 22:42 , Mike Duigou wrote:
>> I've posted an updated webrev with the review comments I have received.
>> One important point to consider:
>> - The current implementations of compute, computeIfPresent, computeIfAbsent, merge are implemented so that they can work correctly for ConcurrentMap instances. For non-concurrent implementations it might be better to fail and throw ConcurrentModification exception whenever concurrent modification is detected. For regular Map implementations the retry behaviour will only serve to mask errors.
>> On Apr 8 2013, at 11:07 , Mike Duigou wrote:
>>> Hello all;
>>> This is a combined review for the new default methods on the java.util.Map interface being added for the JSR-335 lambda libraries. The reviews are being combined because they share a common unit test.
>>> 8004518: Add in-place operations to Map
>>> 8010122: Add atomic operations to Map
>>> putIfAbsent() *
>>> remove(K, V)
>>> replace(K, V)
>>> replace(K, V, V)
>>> compute() *
>>> merge() *
>>> computeIfAbsent() *
>>> computeIfPresent() *
>>> The * operations treat null values as being absent. (ie. the same as there being no mapping for the specified key).
>>> The default implementations provided in Map are overridden in HashMap for performance purposes, in Hashtable for atomicity and performance purposes and in Collections for atomicity.
More information about the lambda-dev